The problem up until now was that the beta does have a lot of new features compared to the alpha, but a lot of them are still in an unfinished state. (Some features are usable, but aren't really a good represantation of the game and thus not really ready for the public.)

A few days ago i've come to the conclusion that i'll release some sort of "pre-beta" of "multiplayer-alpha" version which includes the multiplayer portion of the game (with the server as well as the server source code) but has other stuff (like online leaderboards) disabled for the time being. (Simply because it's unfinished. Additionally i don't even have a server which i could test the stuff on.)

So basically, multiplayer will come first (as a playable alpha/beta version) and all the other stuff will be tested later (once it's finished.)
I still need to fix some things in the multiplayer mode (like server sided leaderboards) before i can release it to the public.